Process for forming bifocal lenses.



H. w. HILL. V

PROCESS FOR FORMING BIFOCAL LENSES. APPLcATN FILED oc'T. 31.1914.

A '1,180,39 5. Patented Apr. 25,1916.

I/VVE/VTOR HARRY W HILL #MAWMW A TTORNEYS bein wasted. as is 'the 'HARRYWILLIAM HILL. (ssoU'rHBRIDGE, MAssAcHUsE-'r'rs ASSIGNOR TO AMERICANOPTICAL COMPANY. OF SOUTHBR-IDGE. MASSACHUSETTS A VOLUNTARY ASSOCIA-TION OF MASSACHUSETTS.

PROCESS FOR FOR-MING BIFOCAL LENSES.

Specification of Letters Patent..

Patented Apr. 25, 1916.

Application filed October 31, *1914 Serial No; 869580. 4 i

To ai?. Ic 710112 it may eonccrn Be it known that I. I-IARRY`V. HILL`, acitizen ot the Ynited States residng at Southbridfe. in the County of-lvorcester and State of Massachusetts. have invented certain new anduseful. Improvements in l''ocesses for Forming Bifocal -Lenses` of whichthe following 'a s pecification.

This invention-relatesto improvements in* bitocal 'lenses. andhaspartiular"'=reference to those orms of bifbcal lense's which consistof two pieces of lass of dissmilar index seem-ed to each other as byfusion.

The leading: object of the'invention is the prorision ot. an improvedprocess for, secpriu the most satist'actory uniting of the 'two partsot'n bifocah and to rednce to a minimum au detect in the lens on accountot' said 'usion.

.i. t'urther object of the invention is the provision of an improvedprocess which will permit of unitin r the najorportion of the blank andsegment without the interposition of any foreign 'matter between theunit- 'ing faces of the blank and segment as has hitherto been deemednecessary.

Another objectofthis intention is the provision of an improved processof' nniting the main and segmentportions of an ophthahuic bitocallensblank in such manner that the entire blank may be used in the formationot' the finished lens in place of a part case with the processes atpresent employed.

Other obieets and advantages of this improved process ot' formin;bifocal lenses should be readily apparent by reference to the followingdescription taken -in conneotion with the aceommirringdrawinf's. and itwill be understoea that any modifieations may bemade pended claimswithout exceedin' the spirit' of this inventon.

Figur-e I represeuts a plan View with the parts in position t'or tusion.Fig. II represents a similar riew at'ter fusion. Fig. III represents asectional View onthe line lII--IIl ot' Fri. I. Vip'. IV represents asimilar View on the-line 'IV- IV of Fig. I. Fig. V representa seetionalView on the 'line Y-V of Fig. ll. Fi VI represents a View similar joFig. IVbut illustratin: a modified Construction.

In the. drawings, in

within the seope of the apdepartinf from or' which simila-:char--acters' of reference are emploj'ed to denote correspondmg pa rtsthroughout thesereral views, the numeral l designates an opht-halmiclens blank having sutably formed there in the eountersink "2 adapted toreceive the segment 3. said segment being forme'd from glass of adifferent index from that ofthe'. blank l. i

In that embodiment of the process-herewith illustrated the segment isformed'with the heveled surrounding edge as ati, and when placed nposition for fusmg one or more a'ngle peces 5 are dsposedwth one face ofthe angle resting upon the 'main blank l and the other 'ace of the:angle bear-ing against the bevet-l onthe segment, the angle member .ormembers I being preferably secu'ed by suitable adhesives to either themain blank l or the segment 3. or to .both. to avoid lability ofslippin'g. By ref- Figs. II- and IV. the

erence particularly to useof these members 5 wllbe clearly underst-ood.and `1t will be seen that they` serve to hold a 'portion of thesegment'. slightly' s'paced from the face *of the -countersink 2, theother end of the segmentrestmg againstturbing the relation of the mainblank and -either of;

segment andwithout injury to said parts.

In Fg.

member 3 has for-med thereon the projection 'or rib t' adaptedto beenaged by the wedge'- like members i' 'for holding the disk at the ed esand keeping itspaced fromthe main portion 1 ot' the blank.- Thewedge-like for mation of the members? permits oftheir adjustiuent toretain-the segment-- in desired. relation to themain blank` whileheatingsotteniug of the thin nember G wllreadily allow the'segnent'to sin-kinto'cotrect position andengagement with the counter-sint( slifhtsoftening VI is illusti'ated a su ht modij-" -fied form of nn" device inwhich the segmt t' 'SO the edge of the cmntersink` if desirechasf "45portion, 'forming segment with a beveled o beat, wherehy the bevelecledge s'sutficiently by proprocesses.

'15 Ic'laim:

1; The-.p"`:ess of fo-nng afbifo caflens blank r consistng in forming.one ofthe two partsto be united with "a slg'htl y shege-led edge,""suppo rtng 7 the' two prts .be ;spaced' 'ela tion by independent.engagnggcl beveled eclge, and` the pa'ts .fto a temperature snffi ;se-sef the bevelel member that sli-l' etlownward' on the pport intoedgesupportmg'sad parts n spaped rela:

ton'by angle members engagng the upp'.. faceof the main blank and thebeveled ,edge .oflthegsegmenm and subjeeting the payts to' heat, Wherebythe beveled edge 'is suffieiently oftened to ermit the segment to slideg doy nwa rd on the angle members nto .en -"gagementw1th the mam blank,and sub ect: nthe pa'rts 'to a contnuing heat-s uficent to fuse `themein'hlank and segment 'into a unitary strueture. v 3-. The p ocess offormng a bifocal lens` blank; conssting in employng a ninp or- 'ton,forming a countersink in' said main edge, supporting sa cl' p'arts' inspa-ced relation by angle members engang 'the upper face of themz n'hlank ancl the beveled edge 'of-the segment, and subjeeting the parte'to softened to permit the segment to slcle doWnWa-;cl on theanglemembers into en: 'g'agement With the man hlanlg eontnung the heatsutficientlyto fuse the mein blank 5.3 and seg'ment into a unit -r gstructure and removing the angle members from the ex posed faces ot themain and segment por tons of the blank, prioto the g'irding ot' thetestltznt product into a finished lens.

4:. The process of formule' ,21 bfocal lens blank, consstng in"fol-mine; main blank with a `counte'sink theren, formng a segment blankwith a. convex curvatu'e ap-` a -oximntely the 'same as thatof thecountersnk, and -Wth a' fia ng betelecl 'eclgeacl alar pacng members on.the .main blank, movng sad members n'to engagement wth thearng bevel ,ofthesegnent to support the segment spaeed fi-'om the' main 'blanksuhjeeting the partshw a` eldn'g tempe-a 'mre whet-eby thebeyelecl edge.is softened' to lloiv the segment to move -clew warcl` into eng'age'mentwith the main blank,- and' 'continuitgsad temperature* to fnse the partstogether.

5. The-process 'of untng blnks for 21 seem-ing: the spcng membersnposition,

suppoi ts to -one ;of the, pa-ts. plcn'g the other part between theuppe` po'tions (f-thi* supports, -wherebv thei-,wo parts 'are held inspace& relatiom' and subjeetin-g the parts' to; a weldng "temperaturewhereby ;one 2 of' the partis caused 'to 'Softn and s "t tle dow nuponend' adhe'e to the other.

The process', of formi-ng; a bfocal lens, coisist'g in polishing thetwosurfaces to be' unit d, sipnortng .the par'ts in r-spaeecl relation. bysnppo1 ts engagng the side only of one of the pa'ts, ndrsubjectg theparte to 'a 'fsing temneratti'e whereby the sides are softened to allowthe parts to move into engagement with-eachother and-unte Withoutbenjding of the polished stu-faces the'eof.

vetm-e on the other 'pat-t, supporting the pats in spacecl relaton bymeansengaging the later-al egeonly of the conyex part, end -subjectngthe' parts to .a fusmg temperature',- Whereby the edge* of the convexmember s caused'to softenand pernnt the mem ton thereof.

in presence of two witnesses( j HARRY'WVILLIAM HILLQ 'XVtnesses: f

- 'H: K.-PARs`oNs, v EDI'IH M. HALVORSEN.

7. Thept'ocess of formng ebfoeal lens, consstng .in grindng endipolishing ai' counterinkl i-one of the parte fot-ming and polshng acor'eponng com-'ex curher tosettledoyvn-uponf and adhe e. to the-'x Iother Without bend lng of thepolished por;

